Extract functions to detect long-enough links.
[Sone.git] / src / main / java / net / pterodactylus / sone / text / SoneTextParser.java
index b3593ec..efb36c4 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Sone - FreenetLinkParser.java - Copyright © 2010–2012 David Roden
+ * Sone - SoneTextParser.java - Copyright © 2010–2013 David Roden
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
 
 package net.pterodactylus.sone.text;
 
+import static com.google.common.base.Optional.absent;
+import static com.google.common.base.Optional.of;
+import static com.google.common.collect.FluentIterable.from;
+
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.Reader;
 import java.net.MalformedURLException;
+import java.util.Comparator;
+import java.util.EnumMap;
+import java.util.Map.Entry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import net.pterodactylus.sone.core.PostProvider;
-import net.pterodactylus.sone.core.SoneProvider;
 import net.pterodactylus.sone.data.Post;
 import net.pterodactylus.sone.data.Sone;
+import net.pterodactylus.sone.data.impl.DefaultSone;
+import net.pterodactylus.sone.database.Database;
 import net.pterodactylus.util.io.Closer;
 import net.pterodactylus.util.logging.Logging;
+
+import com.google.common.base.Optional;
 import freenet.keys.FreenetURI;
 
 /**
@@ -55,40 +64,45 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
        private enum LinkType {
 
                /** Link is a KSK. */
-               KSK("KSK@"),
+               KSK("KSK@", true, false),
 
                /** Link is a CHK. */
-               CHK("CHK@"),
+               CHK("CHK@", true, false),
 
                /** Link is an SSK. */
-               SSK("SSK@"),
+               SSK("SSK@", true, false),
 
                /** Link is a USK. */
-               USK("USK@"),
+               USK("USK@", true, false),
 
                /** Link is HTTP. */
-               HTTP("http://"),
+               HTTP("http://", false, true),
 
                /** Link is HTTPS. */
-               HTTPS("https://"),
+               HTTPS("https://", false, true),
 
                /** Link is a Sone. */
-               SONE("sone://"),
+               SONE("sone://", false, false),
 
                /** Link is a post. */
-               POST("post://");
+               POST("post://", false, false);
 
                /** The scheme identifying this link type. */
                private final String scheme;
+               private final boolean freenetLink;
+               private final boolean internetLink;
 
                /**
                 * Creates a new link type identified by the given scheme.
                 *
                 * @param scheme
                 *            The scheme of the link type
+                * @param freenetLink
                 */
-               private LinkType(String scheme) {
+               private LinkType(String scheme, boolean freenetLink, boolean internetLink) {
                        this.scheme = scheme;
+                       this.freenetLink = freenetLink;
+                       this.internetLink = internetLink;
                }
 
                /**
@@ -100,34 +114,31 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                        return scheme;
                }
 
-       }
+               public boolean isFreenetLink() {
+                       return freenetLink;
+               }
 
-       /** The Sone provider. */
-       private final SoneProvider soneProvider;
+               public boolean isInternetLink() {
+                       return internetLink;
+               }
+
+       }
 
-       /** The post provider. */
-       private final PostProvider postProvider;
+       private final Database database;
 
        /**
         * Creates a new freenet link parser.
         *
-        * @param soneProvider
-        *            The Sone provider
-        * @param postProvider
-        *            The post provider
+        * @param database
         */
-       public SoneTextParser(SoneProvider soneProvider, PostProvider postProvider) {
-               this.soneProvider = soneProvider;
-               this.postProvider = postProvider;
+       public SoneTextParser(Database database) {
+               this.database = database;
        }
 
        //
        // PART METHODS
        //
 
-       /**
-        * {@inheritDoc}
-        */
        @Override
        public Iterable<Part> parse(SoneTextParserContext context, Reader source) throws IOException {
                PartContainer parts = new PartContainer();
@@ -154,15 +165,8 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                 */
                                boolean lineComplete = true;
                                while (line.length() > 0) {
-                                       int nextKsk = line.indexOf("KSK@");
-                                       int nextChk = line.indexOf("CHK@");
-                                       int nextSsk = line.indexOf("SSK@");
-                                       int nextUsk = line.indexOf("USK@");
-                                       int nextHttp = line.indexOf("http://");
-                                       int nextHttps = line.indexOf("https://");
-                                       int nextSone = line.indexOf("sone://");
-                                       int nextPost = line.indexOf("post://");
-                                       if ((nextKsk == -1) && (nextChk == -1) && (nextSsk == -1) && (nextUsk == -1) && (nextHttp == -1) && (nextHttps == -1) && (nextSone == -1) && (nextPost == -1)) {
+                                       Optional<NextLink> nextLink = findNextLink(line);
+                                       if (!nextLink.isPresent()) {
                                                if (lineComplete && !lastLineEmpty) {
                                                        parts.add(new PlainTextPart("\n" + line));
                                                } else {
@@ -170,43 +174,12 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                }
                                                break;
                                        }
-                                       int next = Integer.MAX_VALUE;
-                                       LinkType linkType = null;
-                                       if ((nextKsk > -1) && (nextKsk < next)) {
-                                               next = nextKsk;
-                                               linkType = LinkType.KSK;
-                                       }
-                                       if ((nextChk > -1) && (nextChk < next)) {
-                                               next = nextChk;
-                                               linkType = LinkType.CHK;
-                                       }
-                                       if ((nextSsk > -1) && (nextSsk < next)) {
-                                               next = nextSsk;
-                                               linkType = LinkType.SSK;
-                                       }
-                                       if ((nextUsk > -1) && (nextUsk < next)) {
-                                               next = nextUsk;
-                                               linkType = LinkType.USK;
-                                       }
-                                       if ((nextHttp > -1) && (nextHttp < next)) {
-                                               next = nextHttp;
-                                               linkType = LinkType.HTTP;
-                                       }
-                                       if ((nextHttps > -1) && (nextHttps < next)) {
-                                               next = nextHttps;
-                                               linkType = LinkType.HTTPS;
-                                       }
-                                       if ((nextSone > -1) && (nextSone < next)) {
-                                               next = nextSone;
-                                               linkType = LinkType.SONE;
-                                       }
-                                       if ((nextPost > -1) && (nextPost < next)) {
-                                               next = nextPost;
-                                               linkType = LinkType.POST;
-                                       }
+
+                                       int next = nextLink.get().getNextIndex();
+                                       LinkType linkType = nextLink.get().getLinkType();
 
                                        /* cut off “freenet:” from before keys. */
-                                       if (((linkType == LinkType.KSK) || (linkType == LinkType.CHK) || (linkType == LinkType.SSK) || (linkType == LinkType.USK)) && (next >= 8) && (line.substring(next - 8, next).equals("freenet:"))) {
+                                       if (linkType.isFreenetLink() && (next >= 8) && (line.substring(next - 8, next).equals("freenet:"))) {
                                                next -= 8;
                                                line = line.substring(0, next) + line.substring(next + 8);
                                        }
@@ -218,16 +191,13 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                        if (next > 0) {
                                                parts.add(new PlainTextPart(line.substring(0, next)));
                                                line = line.substring(next);
-                                               next = 0;
                                        }
                                        lineComplete = false;
 
-                                       Matcher matcher = whitespacePattern.matcher(line);
-                                       int nextSpace = matcher.find(0) ? matcher.start() : line.length();
+                                       int nextSpace = findNextWhitespace(line);
                                        String link = line.substring(0, nextSpace);
                                        String name = link;
                                        logger.log(Level.FINER, String.format("Found link: %s", link));
-                                       logger.log(Level.FINEST, String.format("CHK: %d, SSK: %d, USK: %d", nextChk, nextSsk, nextUsk));
 
                                        /* if there is no text after the scheme, it’s not a link! */
                                        if (link.equals(linkType.getScheme())) {
@@ -237,17 +207,17 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                        }
 
                                        if (linkType == LinkType.SONE) {
-                                               if (line.length() >= (7 + 43)) {
+                                               if (lineIsLongEnoughToContainASoneLink(line)) {
                                                        String soneId = line.substring(7, 50);
-                                                       Sone sone = soneProvider.getSone(soneId, false);
-                                                       if (sone == null) {
+                                                       Optional<Sone> sone = database.getSone(soneId);
+                                                       if (!sone.isPresent()) {
                                                                /*
                                                                 * don’t use create=true above, we don’t want
                                                                 * the empty shell.
                                                                 */
-                                                               sone = new Sone(soneId);
+                                                               sone = Optional.<Sone>of(new DefaultSone(database, soneId, false, null));
                                                        }
-                                                       parts.add(new SonePart(sone));
+                                                       parts.add(new SonePart(sone.get()));
                                                        line = line.substring(50);
                                                } else {
                                                        parts.add(new PlainTextPart(line));
@@ -256,11 +226,11 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                continue;
                                        }
                                        if (linkType == LinkType.POST) {
-                                               if (line.length() >= (7 + 36)) {
+                                               if (lineIsLongEnoughToContainAPostLink(line)) {
                                                        String postId = line.substring(7, 43);
-                                                       Post post = postProvider.getPost(postId, false);
-                                                       if ((post != null) && (post.getSone() != null)) {
-                                                               parts.add(new PostPart(post));
+                                                       Optional<Post> post = database.getPost(postId);
+                                                       if (post.isPresent()) {
+                                                               parts.add(new PostPart(post.get()));
                                                        } else {
                                                                parts.add(new PlainTextPart(line.substring(0, 43)));
                                                        }
@@ -272,7 +242,7 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                continue;
                                        }
 
-                                       if ((linkType == LinkType.KSK) || (linkType == LinkType.CHK) || (linkType == LinkType.SSK) || (linkType == LinkType.USK)) {
+                                       if (linkType.isFreenetLink()) {
                                                FreenetURI uri;
                                                if (name.indexOf('?') > -1) {
                                                        name = name.substring(0, name.indexOf('?'));
@@ -289,7 +259,7 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                        if (name == null) {
                                                                name = link.substring(0, Math.min(9, link.length()));
                                                        }
-                                                       boolean fromPostingSone = ((linkType == LinkType.SSK) || (linkType == LinkType.USK)) && (context != null) && (context.getPostingSone() != null) && link.substring(4, Math.min(link.length(), 47)).equals(context.getPostingSone().getId());
+                                                       boolean fromPostingSone = ((linkType == LinkType.SSK) || (linkType == LinkType.USK)) && linkMatchesPostingSone(context, link);
                                                        parts.add(new FreenetLinkPart(link, name, fromPostingSone));
                                                } catch (MalformedURLException mue1) {
                                                        /* not a valid link, insert as plain text. */
@@ -301,8 +271,8 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                                        /* oh, and these, too. */
                                                        parts.add(new PlainTextPart(link));
                                                }
-                                       } else if ((linkType == LinkType.HTTP) || (linkType == LinkType.HTTPS)) {
-                                               name = link.substring(linkType == LinkType.HTTP ? 7 : 8);
+                                       } else if (linkType.isInternetLink()) {
+                                               name = link.substring(linkType.getScheme().length());
                                                int firstSlash = name.indexOf('/');
                                                int lastSlash = name.lastIndexOf('/');
                                                if ((lastSlash - firstSlash) > 3) {
@@ -328,14 +298,84 @@ public class SoneTextParser implements Parser<SoneTextParserContext> {
                                Closer.close(bufferedReader);
                        }
                }
+               removeTrailingWhitespaceParts(parts);
+               return parts;
+       }
+
+       private void removeTrailingWhitespaceParts(PartContainer parts) {
                for (int partIndex = parts.size() - 1; partIndex >= 0; --partIndex) {
                        Part part = parts.getPart(partIndex);
-                       if (!(part instanceof PlainTextPart) || !"\n".equals(((PlainTextPart) part).getText())) {
+                       if (!(part instanceof PlainTextPart) || !"\n".equals(part.getText())) {
                                break;
                        }
                        parts.removePart(partIndex);
                }
-               return parts;
+       }
+
+       private boolean linkMatchesPostingSone(SoneTextParserContext context, String link) {
+               return (context != null) && (context.getPostingSone() != null) && link.substring(4, Math.min(link.length(), 47)).equals(context.getPostingSone().getId());
+       }
+
+       private boolean lineIsLongEnoughToContainAPostLink(String line) {
+               return line.length() >= (7 + 36);
+       }
+
+       private boolean lineIsLongEnoughToContainASoneLink(String line) {
+               return line.length() >= (7 + 43);
+       }
+
+       private int findNextWhitespace(String line) {
+               Matcher matcher = whitespacePattern.matcher(line);
+               return matcher.find(0) ? matcher.start() : line.length();
+       }
+
+       private Optional<NextLink> findNextLink(String line) {
+               EnumMap<LinkType, Integer> linkTypeIndexes = new EnumMap<LinkType, Integer>(LinkType.class);
+               for (LinkType linkType : LinkType.values()) {
+                       int index = line.indexOf(linkType.getScheme());
+                       if (index != -1) {
+                               linkTypeIndexes.put(linkType, index);
+                       }
+               }
+               if (linkTypeIndexes.isEmpty()) {
+                       return absent();
+               }
+               Entry<LinkType, Integer> smallestEntry = from(linkTypeIndexes.entrySet()).toSortedList(locateSmallestIndex()).get(0);
+               return of(new NextLink(smallestEntry.getValue(), smallestEntry.getKey()));
+       }
+
+       private Comparator<Entry<LinkType, Integer>> locateSmallestIndex() {
+               return new Comparator<Entry<LinkType, Integer>>() {
+                       @Override
+                       public int compare(Entry<LinkType, Integer> leftEntry, Entry<LinkType, Integer> rightEntry) {
+                               return leftEntry.getValue() - rightEntry.getValue();
+                       }
+               };
+       }
+
+       /**
+        * Container for position and type of the next link in a line.
+        *
+        * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+        */
+       private static class NextLink {
+
+               private final int nextIndex;
+               private final LinkType linkType;
+
+               private NextLink(int nextIndex, LinkType linkType) {
+                       this.nextIndex = nextIndex;
+                       this.linkType = linkType;
+               }
+
+               private int getNextIndex() {
+                       return nextIndex;
+               }
+
+               private LinkType getLinkType() {
+                       return linkType;
+               }
+
        }
 
 }